To determine the relative contribution at increased bradykinin levels and decreased angiotensin II levels to renal hemogynamic effects of ACE Inhibitors in African Americans and Caucasians. African Americans develop ESRD at a 4-fold higher rate than Caucasians. The magnitude of the problem and the recognition that the renin-angiotensin-system plays a critical role in the progression of renal disease have provided the rationale for testing the hypothesis that VCEIs are renoprotective in humans.